New Year's Day 2006: delayed by a
second
By Jim Wolf
Mon Dec 26, 9:23 AM ET
Get ready for a minute with 61 seconds. Scientists are delaying the
start of 2006 by the first "leap second" in seven years, a timing
tweak meant to make up for changes in the Earth's rotation.
The adjustment will be carried out by sticking an extra second into
atomic clocks worldwide at the stroke of midnight Coordinated
Universal Time, the widely adopted international standard, the U.S.
National Institute of Standards and Technology said this
week.
"Enjoy New Year's Eve a second longer," the institute said in an
explanatory notice. "You can toot your horn an extra second this
year."
Coordinated Universal Time coincides with winter time in London. On
the U.S. East Coast, the extra second occurs just before 7 p.m. on
New Year's Eve. Atomic clocks at that moment will read 23:59:60
before rolling over to all zeros.
A leap second is added to keep uniform timekeeping within 0.9
second of the Earth's rotational time, which can speed up or slow
down because of many factors, including ocean tides. The first leap
second was added on June 30, 1972, according to NIST, an arm of the
U.S. Commerce Department.
Since 1999 until recently, the two time standards have been in
close enough synch to escape any need to add a leap second, NIST
said.
Although it is possible to have a negative leap second -- that is,
a second deducted from Coordinated Universal Time -- so far all
have been add-ons, reflecting the Earth's general slowing trend due
to tidal braking.
Deciding when to introduce a leap second is the responsibility of
the International Earth Rotation and Reference Systems Service, a
standards-setting body. Under an international pact, the preference
for leap seconds is December 31 or June 30.
Precise time measurements are needed for high-speed communications
systems among other modern technologies.
*******
Why don't they delay it by 100 years?
